The National Telecommunications and Information Administration wants a way to block unauthorized cell phone use in prisons, and is asking for our help.

The NTIA has issued a call for comments on plans to find a technical solution for the problem of contraband cell phone use in prisons:

NTIA is seeking comment on technical approaches to preventing contraband cell phone use in prisons. NTIA will develop, in coordination with the Federal Communications Commission, the Federal Bureau of Prisons, and the National Institute of Justice, a plan to investigate and evaluate how wireless jamming, detection, and other technologies might be utilized for law enforcement and corrections applications in Federal and State prison facilities. To assist in its evaluation of these technologies, NTIA requests information from the public on technologies that would significantly reduce or eliminate contraband cell phone use without negatively affecting commercial wireless and public safety services (including 911 calls and other government radio services) in areas surrounding prisons. Comments are requested on or before June 11, 2010.

The complete notice of inquiry is available as a 73-kilobyte PDF download.

As described in the NTIA press release about the call for comments:

“The illicit use of cell phones by prisoners is a danger to public safety and must be addressed,” Assistant Secretary for Communications and Information and NTIA Administrator Lawrence E. Strickling said. “At the same time, we need to make sure that any technical solutions do not interfere with 911 calls, government or other legitimate cell phone use.”

The press release goes on to describe desired solutions as consisting of means to wirelessly jam cell phone signals and detect cell phone signals, as well as “other technologies [that] might be used in federal and state prison facilities to address the issue of contraband cell phone use by inmates.” The due date for any public comments is 11 June 2010.

As things currently stand, however, the FCC forbids cell phone jamming within the United States — a measure that actually applies as much to the Department of Corrections as to private citizens like you and me. To address this, the Senate has already voted to approve a bill that would amend the Communications Act of 1934 specifically to allow cell phone jamming in prisons, and the very similar Safe Prisons Communications Act of 2009 is currently making its way through the House of Representatives.

Of course, wireless industry corporations would rather not let this bill pass the House and get signed into law. The CTIA (formerly the “Cellular Telephone Industries Association”, now “CTI – The Wireless Association”) appears to have influenced the FCC to prohibit testing of prison cell phone jamming equipment that the FCC had previously approved.

The problem, according to the CTIA, is that testing is likely to have a significant impact on cell phone service even outside the prison facility, including the ability to make 911 calls in case of an emergency. Jamming in a number of other countries worldwide, as well as in cases where regulations on jamming equipment were unknowingly violated within the United States, tend to show substantial impact on service outside the intended jamming area. One such case involved a Spokane, Washington school’s attempt to control student cell phone use:

The idea was to prevent students from being able to use their cell phones during class for text or voice. However, when the jammer was turned on, it also jammed the radio that the Spokane County Sheriff had installed in the school that is used for both normal police activity and for swat teams that might be needed. The sheriff’s quote went like this. “While I understand the problems / issues of teenagers and cell phones, interference to emergency communications is not acceptable. As I was not aware of this situation, I will be checking with the FCC enforcement bureau next week for any updates or information.”

Short of building a huge Faraday cage around the prison to prevent the jamming signal from escaping the premises, solving the problem seems to be a difficult task at best. My Faraday cage wallet works well, but it is only a few inches long and wide, and less than an inch thick; hundreds of yards of prison property would be much more difficult, expensive, and impractical to try to enclose in a Faraday cage. Of course, a Faraday cage would also block cell phone signals, which would neatly solve the problem — aside from the impracticality of building a Faraday cage around a prison.

Do you have any thoughts about a solution to this problem?